Override Files--Should they be different from defaults?

[OFelixCulpa]

Yes. I used PSPad, though I normally use WinMerge. I removed all 22 of the files that I had found to be identical, and I see no difference in the looks or function of the template.

The vast majority of the template is controlled from the stylesheet (which the template author also messed up--he called it stylesheet2.css even though it has all the same selectors as the original). There are a few changes in templates\CUSTOM\common\tpl_header.php and languages\english\CUSTOM\header.php. It will be a good template when I am done with it, but I had really expected it to be good the moment I shelled out for it.

So, I spent 50 bucks on a template that is really not that good
I thought I was saving myself some work, but it looks like that may not be the case. Oh well, at least I have nice header and logo images to work with!

On the upside, I am becoming much more familiar with ZenCart this way. Whenever problems arise later on, I will be in a better position to tackle them!

Thanks for your help folks.

[bunyip]

Perhaps someone can explain why this is so. Are there any other pitfalls which I should be aware of with regard to this?

The reason why is the way the cart searches for a template file (governed by functions in includes/classes/template_func.php)
It looks in various places to find a match for the filename, and this particular problem is caused by the preg_match function finding the pattern it was looking for in your modified file name (because you simply added a z at the front, the remainder of the name was a match for the pattern html_header.php).

If you had changed the name in any way other than adding letters at the front or after .php, there would not have been a match.

[OFelixCulpa]

That makes perfect sense. I'll know better next time. I was initially worried that there was some other problem which was causing it to refuse to use the default file. I'm glad that wasn't the case.

Thanks for the explanation.